Efficacy and Safety of Silodosin on Nocturia for Patients With Benign Prostatic Hyperplasia

Inclusion Criteria: * Males of at least 50 years of age, with current diagnosis of benign prostatic hyperplasia * Symptoms of nocturia evidenced by ≥2 episodes per night in average according to 3-day voiding diary * More than total of 8 points on IPSS and 3 points on QoL * Able to provide written informed consent and to comply with all study procedures Exclusion Criteria: * PSA level \> 10 ng/㎖ (except patients who had 4 ng/㎖ \< PSA level ≤ 10 ng/㎖ 6 months prior to screening and identified as negative from biopsy) * Symptoms of postural hypotension * Severe renal disorders or creatinine clearance ≥ 2.0 mg/dL * Severe hepatic disorders or AST or ALT ≥ 3 x upper limit of normal (ULN) * Severe cardiac disorders or development or diagnosis of vascular disorder (unstable angina, myocardial infarction, cerebral infarction, cerebral hemorrhage, coronary artery bypass graft, etc) 6 months prior to enrollment * Any disorder of the gastrointestinal system which could result in altered digestion or absorption, history of gastrointestinal tract surgery except ecphyadectomy * Patients with bladder cancer, cystolith or urethral stricture * Patients with neurogenic bladder * History of acute urinary retention * Indwelling catheter or self intermittent catheterization * Patients with pyuria 1 month prior to screening * History of prostatic cancer * History of prostatic surgery * Patients with uncontrolled chronic disease * Alcoholism or sustained drug dependent abuse 1 year prior to screening * Hypersensitivity to α1A-receptor blockers * Administration of following drugs within according periods prior to screening - 2 weeks: Antimuscarinic agents (Tolterodine, Trospium, Solifenacin, Fesoterodine, Propiverine, Oxybutynin, Flavoxate, etc), Anticholinesterase agents (Neostigmine methylsulfate, etc), Cholinergic agonists (Bethanechol Cl, etc), Benign prostatic hyperplasia agents (Tamsulosin HCl, Prazosin HCl, Terazosin HCl, Doxazosin mesylate, Silodosin, Naftopidil, etc), Tricyclic antidepressants (Amitriptyline, Clomipramine, Dosulepin, Doxepin, Imipramine, Quinupramine, etc), 6 months: 5-α-Reductase Inhibitors (Finasteride, Dutasteride) * Presence of a condition or abnormality that in the opinion of the investigator would compromise the safety of the patient or the quality of the data